Telephone-exchange system.



A. E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED NOV. 29. 1915' 7 1,244,999. Patezited Oct. 30,1917.

lnvenior: 335*" Albvn Elana/ell ALBEN E. LUNIDELL, OF NEW YORK, N. Y., i

INCORPORATED, OF NEW YORK, N.

SSIGNOR T0 iWESJ'IEBN ELECTRIC COMPANY,

Y.,-A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE sYsTnM.

' Specification of Letters Patent:

Patented oet. so, 1917.

Application filed November 29, 1915. Serial No. 64,060.

To all whom it may concern:

e it lmown that L'ALBEN E. L UNnnLL, a citizen of the United States, residing at New York, in the county of Bronx and State of New York, have invented certain new and useful Improvementsin Telephone-EX- change Systems, of'which theifollowing is a full, clear, concise, andexact description.

This invention. relates to telephone eX change systems and more particularly to signaling systems for telephone'exchang'es.

It is the object of this inventi'on'to PTO, vide an improved signaling arrangementoperable upon the 'establishmentofa connection between a calling line and one of a plu rality of classes of called lines, means being provided for releasing the arrangement upon the signaling of a called line belongingto either class,

According to the main feature of this invention, if a connection is established between a calling line and a called line of a certain class (e. g; a line leading to an op erators position), the signaling'apparatus, which was actuated upon the completion of the connection, is automatically restored upon the actuation of a signal associated with the called line. i

'The drawing represents a telephone eX- change system embodying the features of the present invention,

The invention will be more readily under stood'from thefollowingdetailed descrip tion and the appended claims.

The subscriber located at substation 10, desiring to obtain a connectionwitha station 11, removes his receiver from the switch'-, hook for causing the displaying of 'a signal 12 in the welleknown mannengA connecting operator inserts thereupon an answering plug13into' an answering jack' 14 fore-x- I tinguishing signal 12 and for taking. the

orders of the calling, subscriber. She then setslup the number of'the desired party on a well-known revertive impulse. sender 15 for controlling selector switches 16 and 17 to select the desired line. I

' Asequence switch (not shown)v associated with selector 16 controls springs 18, 19 and 20. During the 'set-tingYof the selectors,

this sequence switch is in position 11, :and

the extent of travel of theselector switches is controlled by the successive opening and closure of a contact 21 provided inh a controlling, ,circuitat, sender 15 and. a stepping magnet 22 controls the stepping of the sender in accordance with impulses sent from the switches'back to the sender. As such selector switches and their circuit arrangements are well known in the art, and as they do-not form a part of the present invention, their detailed description does not. seem necessary. Sequenceswitch spring 20 controls the holding of the selected trunk during conversation. After the selector switches'have been set, the sequence switch is mo'vedout of position 11 into position 14 for extending the calling to the called line through springs 18 and 19.

The signaling of the called subscribers station takes place now. Upon the setting of selector switches 16 and 17 a'relay 22 becomes energized. by through a circuit closed at a sequence switch contact actuated upon the setting of the selector switch 17. The operation of the sequence switch arranged to control the contact 60 is described in a patent to F. N. Reeves, No. 1,218,804. Upon energization, relay 22 closes a circuit from ground, through its armature and front contact, and

the windings of relays 23 and 24, to grounded'battery, Only relay 24 becomes energized, a shunt being closed around the winding'of relay 23. .Relay'24 closes a signaling circuit from ground through ringingflcurrent generator 25, interrupters' 26 and 27,

or from grounded battery, throughinterrupter 27, the winding of a marginal rela'y'28, the lower front contact and armatureof relay 24, wiper 29 of connector switch,17,,.line conductor 30, the bell at substation 11, line conductor 31, brush 32' of connector17, andtheupper armature and front contact of relay 24, to ground. Relay 28 energizes only upon the removal of the receiver at the called station, and opens at its back contact the shunt around the winding of relay 23, which then becomes energized, short-circuits relay 24 and closes a lockingcircuit for itself.

Upon the deenergization of relay 24, a circuit is closed from grounded battery,

through the secondary winding of a repeating coil 32, the winding of a supervisory relay 33, the bottomcontact of-sequence switch spring 19, the called substation loop, the top contact of sequence switch spring 18, andthe secondary winding of repeating coil 32, to ground. Relay 33 becomes energized 7 energizing this relay,

and causes in the WQll-lillOWll11121111161 the actuation of a superrisory signal, indicating to the connecting operator that the desired station has answered.

It the calling station 10 desires to obtain a connection to a special operator whose telephone set is indicated at 3%, the connecting operator will cause the setting of switches 16 and 17 in the same manner as above described to selectan outgoingline terminating in a jack'35 at the special operators position. Upon the energization of relay 2%, a circuit isclosed from the ringing current source through the winding of relay 23, the lower front contact and armature of relay 2%, connector brush 2 9, conductor 36, condenser 37, thelett-hand winding of a relay 3S, conductor 39, connector brush 327. and the upper armature and front contact of relay 2%, to ground. The left hand'winding of relay 38 is responsive to alternating current, whereby armature lO will be attracted. Armature Ail controlled by the right-hand winding of relay 38 is released and a circuit is closed from ground through 41, contact -22, the winding of a relay 43, a lamp signal it, and the winding of relay 4 .5, to grounded battery. Relays l3and and lamp t r will be actuated, and relay {l5 closes a circuit for an audible signal 45, whereby the special operator will be informed that a call is awaiting attention.

The above described signaling circuit, including the winding of relay. 28, does not permit the passage of suthcient current for In ordeiy lioweyer, to make possible the. tripping of the ringing, '5. e. the opening of the signaling circuit immediately upon the setting of the selector switches, a circuit is closed from grounded battery, through conductor 46, the armature and front contact of relay e3, resistance d6, conductor 36, connector brush the lower armature andtront contact of relay 24:, and the winding of relay 28, to the ringing current source. Relay 28 becomes energized and opensthe signaling circuit in the above describednianner. Relay 33 controlling the supervisory signal, however, will not be energized, due-to the closure. of a shunt around its Winding through conductor 4:6. it should be mentioned at this point that the tripping battery connected tot-he interrupter 2-7 is of greater voltage than the battery connected to the repeating coil 32.

As soon as the specialoperator inserts her plug a? into jack 35, a circuitis closed from grounded battery, through resistance as, the sleeve contacts or plug 45 andjack 35, and the right-hand winding of relay 38, to ground. Relay 38 attracts its armature e1, opening thereby the circuit of relays et3 and +25, and lamp ll-L. Relay opens the shunt around the windings of relay 33, and

this relay becomes energized and actuates the supervisory signal to the connecting 0perators position. The circuit for relay 33 extends from grounded battery, through 33, 19, 29, 36, resistances 4:6 and t9, the tip contacts of acl: 35, and plug a7, and the primary winding of a repeating coil to ground.

The special operator by depressing her listening key 5l rnay connect'in circuit her telephone set 3% to 'converserwith the calling subscriber; A I 1 p The release of the apparatus employed in the extension of calls to subscribers lines or operators positions may be controlled in any welldrnown manner.

lVhat is claimedis: A

1. In a telephone exchange system, anincoming and an outgoing line, means for establishing a connection between said lines, a signaling circuit closed upon the establishment of said connection, a signal in said circuit associated with the outgoing line, a relay in said circuit actuated in'response to the operation of said signal, and means operatire thereupon for renderingsaid circuit ineiie'ctive. I V k M i 2. In a telephone exchange system, a plurality or lines,nieans for establishing a'connection betii een calling and called lines, a signaling circuit closed upon the establishment oi said connection, a sigi'ial in said circuit associatedwithsaid c'alledline, a relay in said circuit energized in response to the actuation of saidsignal, and means operative thereupon for opening said circuit.

3. Ina telephone exchange system, incoming lines and a plurality'ot classes or out-going lines, means for establishinga connection between a calling incoming-"and a called outgoing line, a signaling'circuit, closed upon the establishment of said connection, a relay associated with each of said, incoming lines, a signal associated with each of said outgoing lines, a manually operable switch associated with each outgoinglinfe belonging to one classgnie'a'ns ooperative upon the establi'shnieiit of a c Onnection :for closing a signaling circuit including the "relayassoci'ated with the calling incoming line and the signal associated with'thejcalled outgoing l ne, means operative n response'lto the ac; tuation of the switch or the called'joutgoing nection between a calling and a c'alledli'ne,

a signaling circuit closed upon the establishment of said connection, a signal in said 'cir cult assoclated with said called line, a man ginal relay in said circuit prevented from being energized upon the closure thereof, and means operative in response to the actuation of said signal for permitting the energization of said marginal relay.

5. In a telephone exchange system, incoming lines and a plurality of classes of outgoing lines, means for establishing a connection between a calling incoming and a called outgoing line, a signaling circuit closed upon the establishment of said connect-ion, a marginal relay associated with each of said incoming lines, a signal associated with each of the outgoing lines, a manually operable switch associated with each of the outgoing lines belonging to one class, means operative upon the establishmentof a connection for closing the signaling circuit including the relay associated with the calling incoming line and the signal associated with the called outgoing line, said relay being prevented from energizing upon the closure of said circuit, means operative in response to the actuation of said switch for permitting the energization of said relay, means responsive to the actuation of a signal associated with an outgoing line belonging to another class for permitting the energization of said relay, and means operative upon the energization of said relay for opening said signaling circuit.

G. In a telephone exchange system, an incoming line and an outgoing line, means for interconnecting said lines, a relay associated with the incoming line, a signal associated with the outgoing line, a circuit extending from the free pole of a relatively high voltage grounded battery through said relay and signal to ground, closed upon the establishment of said connection, a, relatively low voltage grounded battery, and means controlled by said signal for connecting the free pole of said last mentioned battery to said circuit. i

7 In a telephone exchange system, an incoming and an outgoing line,means for interconnecting said lines, a marginal relay associated with the incoming line and a signal associated with the outgoing line, a relatively high resistance circuit extending from the free pole of a relatively high voltage grounded battery through said relay and signal to ground, closed upon the establishment of said connection, a relatively low voltage battery, and means operable in response to the actuation of said signal for closing a relatively low resistance circuit from the free pole of said relatively high voltage battery through the winding of said relay to the free pole of said relatively low voltage battery. 7

8. In a telephone exchange system, a plurality of lines, means for establishing a connection between a calling and a called line, signaling apparatus actuated upon the establishment of said connection, a'relay controlled thereby, a called station from which said relay may be controlled, a signal controlled by said relay, means operable upon the actuation of said relay under the control of said apparatus for actuating said signal and restoring said apparatus, and means operable upon the actuation of said relay under the control of said station for restoring said signal. 7 In witness whereoi I hereunto subscribe my name this 27th day of November, A. D.

ALBEN E. LUN DELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of-Patents, Washington, D. 0. 

